Mine cooling system



Feb. 22, 1938. D. CJLINDSAY MINE COOLING SYSTEM Filed March 21, 1955 3 Sheets-Sheet 1 .lllullllllllllil 3 ATTORNEY.

Feb. 22, 1938, D. c. LINDSAY MINE COOLING SYSTEM 5 Sheets-Sheet 2 Filed March 21, 1935 Kk Sow mm a m s T 0 mv wv C E Do L a m mv N R mv W k 0% ww av a Hmw m K 009w Nw \w I l l I I l l I l l I I l I I I II I QW |H HHI HHHll ll l l l l lHH-HHH.HUN! l I I I l I I I HHH I I HHHHHIHHHPH H NV Hl l l l l l l lN IHHHl l lHHHl l lHH HI I I IH H| w fix:

ATTORNEY.

Feb. 22, 1938. D. c. LINDSAY MINE COOLING SYSTEM Filed March 21, 1935 3 Sheets-Sheet 3 A lio-rn e3.

Patented Feb. 22, 1938 UNITED STATES PATENT OFFICE MINE COOLING SYSTEM rier Corporation, Newark, N. J., a

of Delaware Application March 21,

13 Claims.

This invention relates to the .cooling and conditioning of air within deep mines or similar chambers, and more particularly to the distribution of conditioned air throughout the working of such a mine.

The operation of mines presents many problems collateral to the main problem of removing ore. One of the most troublesome and difficult of these collateral problems is encountered in ventilating and cooling the mine; and the difficulties increase with each increased increment of depth. It is well known, for example, that the rock temperatures increase at the rate of about one degree F. for each 220 feet of depth on the Witwatersrand, in the Union of South Africa, and as much as one degree F. for each fifty-five feet in depth in some other fields. Further, the temperature of any air introduced into the mine increases at the rate of approximately one degree F. for each two hundred feet of depth, as a result of the increased air (barometric) pressure. In addition to these factors, the air absorbs large quantities of moisture from the rocks, and other natural water sources, in the mine.

In shallow mines these factors are of relatively little importance, and straight ventilation is usually adequate. However, in mines of several thousand feet depth, these factors become extremely important; many mines in various fields 30 are now at depths where the condition of the air has become so oppressive that human beings cannot work effectively therein. Beyond these critical depths the hazard increases and the life of many mines can be prolonged only through measures to correct these conditions. If the mines are to be driven down to greater depths, and are to be worked at these low levels, it becomes imperative that some means for cooling and dehumidifying the air be provided.

If the conditioning equipment is placed on the surface level, and air is blown down into the mine it is readily apparent that there is a definite limit in depth beyond which its cooling effectiveness will be lost. .Hence, although. the difiiculties are great applicant proposes to place his conditioning equipment down in the mine at or near the point of usage. In previous arrangements of this type, one set of air conditioning plant has been provided in the mine, and the cooled air distributed from this point throughout the workings. However, it is not infrequent that the size of such an apparatus is so great that it cannot be gotten into the mine. Further, in certain types of mines, air distribution from one point is a physical impossibility. Another discorporation 1935, Serial No. 12,158

advantage of such an arrangement resides in its relative inflexibility, i. e., more equipment cannot readily be added to such a system for the purpose of cooling new and additional mine workings. 5

The principal object of this invention, then, is to provide a conditioning system for cooling the air within the lower reaches of a mine.

Another object of the invention is to utilize the worked out portions of the mine as air conduits.

Still another object of the invention is to divide the conditioning equipment into a plurality of units located on a plurality of levels, and to utilize the equipment on the higher levels for correcting the condition of the air discharged upwardly from the lower levels, and simultaneously, for adding to the volume of air from the lower levels.

A further object of the invention is to provide 20 a flexible type of air conditioning system to which additional units may be added for conditioning the air of new workings.

According to the present invention a method for the purpose in view consists in drawing air from the outside into one of the lower levels of the mine or chamber, cooling and conditioning this air, discharging it into or passing it through working passages at this lower level, and then passing it through working passages at a higher level where it is mixed with freshly conditioned air. The invention also relates to a system for carrying out this method according to which air conditioning units are provided at various levels of the mine or chamber, the unit at one of 35 the lower levels conditioning the air before discharging it into the working passages at this level, the other units successively conditioning au which they add to the air from a lower level and which is passing into working passages at a higher level.

The invention will now be described with reference to the drawings accompanying the speci fication wherein:

Fig. 1 is an isometric View of a foot wall type mine;

Fig. 2 is an elevational view of the mine of Fi 1;

Fig. 3 is a sectional View taken on the line III-III of Fig 2; and

' Fig. 4 is an isometric View on an enlarged. scale of a portion of Fig. 1 showing a conditioning chamber and air passageways associated therewith. r

Referring to Fig. 3 it will be seen that the ore which is being mined is shown as lying in an inclined plane, the main access shafts, galleries and cross cuts being on the underside of the ore, and the plane containing the ore is usually referred to as the reef or lode, while the country rock on the underside of the ore is described as the footwall and the country rock on the upper side is frequently referred to'as the hanging wall; A foot 'wall'type mine referred to in the present description is one in which the main access shafts or inclines, levels, cross cuts and so forth are all driven in the footwall side of the reef;

In the drawings, similar designations referring to similar parts, numeral designates the main, or downcast shaft of the mine. As can be seen,

7 this shaft passes downwardly at an angle to the plane'of the earths surface, and approximately parallel to, but beneath, the plane of the gold bearing reef 6. 7

Various footwall drives Ia, 1b,.Ic, etc., extend horizontally from the shaft 5, in such directions,

that all parts of the various footwall drives are approximately equidistant from the 'gold bearing,

reef and at depths of about 200 feet. Since the downcast shaft 5 is approximately parallel to the gold bearing reef '6, it is "apparent thatthese footwall drives Iw,i'Ib, etc. do'not enter the reef 6. Cross cuts'8a,.8b, 80, etc., are driven at right angles from the footwall drives 1a, 1b, 10, etc. and at intervals of 500 feet apart into the gold bearing reef 6. The reef drives 9a, 9b, 90, etc.,

. are in'the s'ameplane, andfgen'erally parallel to the footwall drives (Figs. 2 and 3) and about 350 feet therefrom.

As 'is particularly clear in Fig.3, one footwall drive, one reef drive'and connecting cross-cut drives form one level.

Inc, I 0b, IIJc, etc., are driven into the reef. These stopes follow the reef from one reef drive to another, for example, stopes 'llla exten'd ffrom reef drive 9a to reel drive 91). In other words, the entire reef is honeycombed withpstopes. In this manner, the greatest amount of ore can be removed with the least danger of cave-ins.

As can be seen from Fig. 2, the 'mine is in the form of an arrowhead. The point'of the arrow is constantly driven downwards, and the rear part of the arrow is constantly being widened. On the lower levels of the mine, the stopes are very narrow, and few in number, while on the'upper levels, the stopes are wider and more numerous.

Hence, the space to be cooled constantly increases as the air flows upwardly through the.

workings. I r u 7 Considering now the actual air conditlonin'go'f' such amine as has been herelnbefore described,

applicant proposes, in 'general, to draw' air from the surfacewthrough the downcast shaft '5 into the lowermost footwall drive Ia. On this lowermost level, either in the footwall drive "la, in the cross cut'8a, or in reef drives 8a, this air 'will be conditioned. Sinceit maylater be} desirable to extend both thefootwall and the re'ef drives, ap-

plicant proposes toplace his conditioning unit IIa in chamber IZaformed in cross cut 80,} The.

unit Ila may b'e 'of any well known design,

either ofthe spray type or the'surface type. In-

any event, a coldliquid, either water, or brine, from any available source,'isfcirculated through theunit tocool air passing therethrough. The" chamber is. closed off bymeans jof dampers 13a at the'entzanceendof'unlt I Ia. A fan 14a draws air from the downcast shaft 5, through footwall drive 1a, andthrough'fthe"cross1cutdrivestBa, ito

V In order to work the reef to "the greatest possible extent, various stopes ious combinations of these three factors which produce an equal heat dissipation from the body,

i. e., equal cooling effect as measured by a katathermometer, are termed conditions of equal comfort. It will be assumed, for purposes of illustration, that the air discharged by fan Ma will have a dewpoint temperature of 75 degrees and a dry bulb temperature and movement suitable for comfort. passes into reef drive 9a, and from there up wardly through stopes IOa.

As canbe seen, the space to be cooled increases with each succeeding level. 7 To take care of the increased cooling requirements, a unit II b is placed in chamber .I2b of the outside'cross cut '81), the inner'cross cuts being closed by doors I'Ib. Fan Mb draws air fromshaft 5 through footwall drive Ib, through crosscut 8b and into chamber From the fan the air- I2b. The air is cooled and dehumidified to such I an extent that when it is discharged from the chamber I2b into the reef drive 9b and is there mixed with the air from the stopes Illa, the mixture will have a dewpoint temperature of '75v .de-

grees F. Further, the volume of air handled by fan I 4b is just suificient when added to the volume of air from'stopes IOa, to maintain the'desired air circulation through reef .drive '9band stopes IIIb. Similarly, fan I 40, located in chamher I 20 of the outside'cross cut 80, the innerrcross 7 outs being-closed by doors I 10, draws airfrom shaft 5 through footwall drive "I0, cross cut 8c; and into conditioner I-Ic. This volume ofair is likewise cooled and dehumidified to such an 'ex-.

tent that when mixed with the air from stopes- IOb (a mixture of air from stopes Illa and con-' ditioner unit Ilb) the mixture will have a dewpoint temperaturefof degrees F; and be sufficient in volume to create adequate circulation through reef drive and stopes I00. In a like manner, various: other conditioning units may be placed upon the succeeding levelsof the mine, and the volume of air handled thereby may be mixed with the airfrom the stopes of the levels therebeneath. 'It-is, of-course, apparentthat the' temperature of the air leaving unit I Ib is not the same as the temperature. of air leaving'unit I Ia; and likewisejthe temperature of air leaving'unlt IIc may be different from the air temperatures at Ma and Nb. In general, the ai'r'temperature at thevarious units I Ia, IIb and H0 will all differ-one'from the other. Thermostats I5a, I51) and I5c located in stopjes Illa; Illband .I0c may 7 be utilized to control the temperature of air discharged from conditioning units Ila, .IIb and IIc respectively thus to controlthe temperature of air inthe respective stopes.

In any event, theiair will proceed upwardly through the stopes and will finally bedischarged into the'atmosphere at the earths surface.

While'applica'nt has described hereinbeforethe conditioning of air from the main shaft,'and;the;

addition of this ;.air to the airpassingupward from'theilower levelsQitisequally possible to accomplish substantially the same results ln'a J slightly different manner, For'example, apart of the? air from the stopes Ina maybe led' tliroughtunnel lfia into chamber I2b, wherein it will be conditioned, Jmixedwith untreated airi front shaft to augment the volume and discharged into reef drive 91) and stopes b. The air not drawn into the tunnel 16a. continues through stopes Illa to reef drive 9b, as formerly. If desired, a mixture of air from the stopes and air from shaft 5 may be conditioned and then discharged into the reef drives. The particular arrangement employed will in general depend upon the conditions encountered in individual mines.

In general, then, applicant has provided what may be termed a regenerative, or corrective type of cooling system. Thus, a small volume of air is conditioned to cool the lowermost levels of the mine. After this air has served its primary purpose it passes upwardly into the succeeding levels of the mine, where its volume is augmented and its condition is corrected so that the mixture may be used for cooling this level. In other words, a volume of air is passed from one working level to another, and successive corrections and augmentations are made to it at successively higher levels. By correcting the temperature and humidity condition of the air at each succeeding level, and by augmenting the volumes to maintain a desired circulation, conditions of approximately equal comfort are maintained throughout the working of the mine.

Since certain changes may be made in the method without departing from the scope of the invention and since various changes may be made in the type and arrangement of the conditioning apparatus shown and described, it is intended that the drawings and description shall be construed in an illustrative and not a limiting sense. Further, where the terms stopes, cross cuts, reef drives and footwall drives are used, it is intended that these terms shall be construed in a descriptive and not a limiting sense.

In the accompanying claims, the term freshly conditioned air shall be understood to refer to air of any nature and from any source or sources which has been conditioned in an air conditioning unit or apparatus, and whose condition since leaving said unit or apparatus has not been materially changed. This air may be fresh air from the air supply shaft, air which has already circulated through one or more levels of the mine and which may or may not have been previously conditioned, or a mixture of fresh air and such previously circulated air.

I claim:

1. The method of conditioning and ventilating a mine having a plurality of levels, a lower level having less volumetric air capacity than a higher level which comprises drawing air into said lower level of said mine, conditioning said air, discharging the conditioned air into the working passages of said lower level, drawing a second volume of air into said higher level of said mine, conditioning said second volume of air on said higher level, mixing said second volume of air with the volume of air from the working passages of the lower level, and circulating said mixture throughout the working passages of said higher level, whereby said higher level is supplied with a greater quantity of air than said lower level to meet the greater ventilation requirements of said higher level, and whereby said higher level and said lower level are each desirably conditioned.

2. The method of conditioning and ventilating a mine having a plurality of levels, the lower levels having less volumetric air capacity than the higher levels which comprises drawing air from a main shaft into the footwall drive of one of the lower levels of said mine, conditioning said air on said lower level, discharging the conditioned air through a cross cut into the reef drive of said lower level, passing the air through said reef drive and through the stopes into the reef drive of a higher level of said mine, augmenting this air with a volume of other air freshly conditioned at the higher level, and circulating this mixture through the reef drive and stopes of the higher level, whereby said higher level is supplied with a greater quantity of air than said lower level to meet the greater ventilation requirements of said higher level, and whereby said higher level and said lower level are each desirably conditioned.

3. The method of cooling and ventilating a mine having a plurality of levels, the lower levels having less volumetric air capacity than the higher levels which comprises conditioning a volume of air on one of the lower levels of said mine, passing said conditioned air through the working passages of said lower level, discharging the air into the working passages of the upper levels of said mine, and successively adding volumes of freshly conditioned air conditioned at higher levels of the mine to the air from the lower levels at successively higher levels, whereby all levels of the mine are adequately ventilated and desirably conditioned.

4. The method of cooling and ventilating a mine having a plurality of levels, the volumetric air capacity of the different levels decreasing as the depth of the mine increases which comprises conditioning a first volume of air on one of the lower levels of said mine, passing said conditioned air through the working passages of said mine, and successively adding volumes of air conditioned at higher levels of the mine to said first volume of air at successively higher levels of said mine, whereby each of the levels of the mine is provided with an adequate quantity of air for ventilating purposes, and whereby desired atmospheric conditions are maintained in each of said levels.

5. In a system for cooling and ventilating a mine having a plurality of levels, the volumetric air capacity of the different levels decreasing as the depth of the mine increases, a shaft for intaking air from the surface level, an air conditioning unit on one of the lower levels of said mine, a passageway for intaking air from said shaft to said unit, means for discharging conditioned air from said unit throughout the workings of said level, and a plurality of other conditioning units located on a plurality of successively higher levels for successively adding volumes of conditioned air to the conditioned air from said first mentioned unit.

6. In a system for cooling and ventilating a mine having a plurality of levels, the. volumetric air capacity of the different levels decreasing as the depth of the mine increases, a shaft for intaking air from the surface level, a plurality of conditioning units located on a plurality of levels of said mine, means including the lowermost unit for conditioning the lowermost level and for discharging the used air upwardly into successively higher levels, and means including other units for adding freshly conditioned air at higher levels to the mixture of air received from the levels therebeneath.

'7. In a system for cooling and ventilating a mine having a plurality of levels, the volumetric air capacity of the different levels decreasing as the depth of the mine increases, a plurality of levels of said mine, a shaft for intaking air from the surface to each of the units, means including the lowermost unit for dischargingconditioned air into the lowermost working passages of the mine and then upwardly into the higher working passages; and means including the remaining units on successively higher levels for discharging freshly conditioned volumes of air into the air received from the working levels therebeneath.

, 8.'In a system for cooling and ventilating a mine having a plurality of levels, the volumetric air capacity of the different levels decreasing as the depth of the mine'increases, a shaft for intaking air from the surface to thevarious levels of said mine, a plurality of air conditioning units located on a plurality of levels of said mine, the lowermost of said units being adapted to condition air from said shaft and to discharge the conditioned air through the working passages of said level and then upwardly to the higher levels of the mine, the remainingunits being adapted to recondition the'air received from'the levels therebeneath and to discharge the'conditioned air into the workingpassages and upwardly into the higher levels, and means for introducing untreated air from said shaft into the mine workings on a'plurality of levels.

9;. In a system of cooling and ventilating a mine having a plurality of levels, the volumetric air capacity of the different levels decreasing as the'depth of the mine increases, a shaft'forintroducing air from the surface into a plurality of levels of said mine, means for conditioning air from the shaft and for discharging it through the workings of the lowermo'stleveland "then upwardly through the higher working passages, and means for reconditioning at higher levels air received from the levels 'therebeneath and for mixing therewith untreated air intaken from said shaft. r

10. In a system for cooling and ventilating a mine having a plurality of levels, the volumetric air capacity of the different levels decreasing as the depth of the mine increases, a shaft for intaking air from the surface to the various levels of said mine, a plurality of air conditioning units located at different levels of the mine, means including the lowermost of said units for conditioning air from said shaft and discharging said conditioned air through the working passages of the lowermost level and then upwardly to higher levels of the mine, and means including other of said units at higher'levels of the mine for C011! ditioning air received from the levels therebeneath and also air received from said shaft, and for discharging the air conditioned by said other units into the working passages of the mine.

11. In a system for cooling and ventilating a mine having a plurality of levels, .the volumetric air capacity of the different levels decreasing as the depth of the mine increases, a plurality of air, conditioning units located at a plurality of levels in the mine, a shaft for introducing air from the surface into a plurality of levels of the mine, means including the lowermost unit for conditioning air from the shaft and discharging it through the workings of thelowermost level, the

conditioned air then flowing upwardly into work-- ing passages at higher levels, and means includthrough the working passages at said lower level, a

the air then being discharged upwardly through the mine, and means for conditioning at a higher level of the mine other air from the shaft and for adding, at a higher level of the mine, said other air to the air from said lower level.

13. The method of cooling-and ventilating a mine having a plurality of levels, the volumetric air capacity of the different levels decreasing as the depth of the mine increases, which comprises conditioning air at a'lower level of the mine, circulating said air through the workings of said:

lower level, then supplying said air to a higher level of the mine, supplying to said higher level other air drawn from the outdoor atmosphere, conditioning at said higher level air supplied thereto, and circulating all of the air supplied to said higher level through the Workings of said 7 higher level.

DANIEL C. LINDSAY; 

